Long Tail Cast On

[anne312]

Is there a trick to figure out how much yarn to pull out to do the long tail cast on so as not to run out before finishing a long cast on or having too much left over when finished? I have to co 400 stitches and I can't even begin to figure out how much yarn to allow for the co. Any tricks out there?
Thanks,
Anne

[Mystery_Gyrl]

Usually I let a few inches of yarn hang from my needle than wrap the yarn around the needle for the approximate number of stitches needed. Some people have suggested to me for casting on a large amount of stitches to wrap the thread for about a third or quarter of the stitches required remove the yarn from the needle holding/pinching where you stopped measuring from where you started and stopped than pulling out however many inches or feet you would need to get the complete amount of stitches (e.g. you need 200 stitches, wrap 50 stitches around needle, 50 sts = 8", pull out 24" more of yarn). However, this latter method sounds like extra work.
Katrina